British-born hostage Luke Somers, who had been working as a photojournalist, has been killed after a failed rescued attempt in Yemen.

His death was confirmed by his sister, Lucy, who told Associated Press that the family had been informed by the FBI of his death. His sister said: "We ask that all of Luke's family members be allowed to mourn in peace."

A US official has confirmed that Somers had died after being shot during the botched rescue operation. By the time he was located and flown to the naval base in the Gulf, Somers was pronounced dead.

Barrack Obama released a statement condemning the "barbaric murder" of Luke Somers.

"On behalf of the American people, I offer my deepest condolences to Luke's family and to his loved ones. I also offer my thoughts and prayers to the family of a non-U.S. citizen hostage who was also murdered by these terrorists during the rescue operation. Their despair and sorrow at this time are beyond words."

"It is my highest responsibility to do everything possible to protect American citizens. As this and previous hostage rescue operations demonstrate, the United States will spare no effort to use all of its military, intelligence, and diplomatic capabilities to bring Americans home safely, wherever they are located. And terrorists who seek to harm our citizens will feel the long arm of American justice."

The American president said that the United States had been "using every tool at our disposal to secure his release."

"Earlier this week, a video released by his terrorist captors announced that Luke would be killed within 72 hours. Other information also indicated that Luke's life was in imminent danger."

"Based on this assessment, and as soon as there was reliable intelligence and an operational plan, I authorized a rescue attempt yesterday. I also authorized the rescue of any other hostages held in the same location as Luke."

"Luke was a photojournalist who sought through his images to convey the lives of Yemenis to the outside world. He came to Yemen in peace and was held against his will and threatened by a despicable terrorist organization."

Barrack Obama condemned AQAP's "callous disregard for Luke's life", claiming it was "more proof of the depths of AQAP's depravity, and further reason why the world must never cease in seeking to defeat their evil ideology."

Obama also thanked the soldiers who took part in the botched rescue operation: "As Commander-in-Chief, I am grateful to the U.S. forces who carried out this mission as well as the previous attempt to rescue Luke, and to the dedicated intelligence, law enforcement, and diplomatic professionals who supported their efforts."

The President finishes the statement: "We remain determined to do our utmost to bring them home, and to hold those who have done them harm accountable."

Luke Somers, 33, originally moved to Yemen to work as a teacher before pursuing a career as a photojournalist. He was kidnapped in the Yemeni capital of Saa'na in September 2013.

A 85-second video was released on Thursday in which Somers appeared begging for his life. His captors, militants from Al-Qaeda in the Arabian Peninsular, said that they would kill Somers if there unspecified demands were not met within three days.

In the video, Somers said: "It's now been well over a year since I've been kidnapped in Sana'a. Basically, I'm looking for any help that can get me out of this situation. I'm certain that my life is in danger.

"So as I sit here now, I ask if anything can be done, please let it be done. Thank you very much."

Nasser bin Ali al-Ansi, a senior AQAP (al-Qaeda in the Arabian Peninsula) militant, declared in the video that "the American hostage held by us will meet his inevitable fate" if the unspecified demands were not met within three days.